Linux is considered as most user-friendly UNIX like operating systems.

Apple OS X is most popular UNIX operating system for desktop usage.

2. Compare Linux with Windows?

Linux
1) Linux is opensource, the complete source code for Linux is available.
2) Linux is the GPL-licensed operating system, you are free to modify that software and use and even republish or sell it.
3) Download once and install it on as many PC you want.
4) Online peer support from the community via forums and online search.Windows
1) Source code for windows is not available.
2) You can modify or redistribute Window operating system.
3) In Windows, you are bounded to use one license in One PC only.If you have to install it on other PC you need another Licence.
4) Paid help desk support.

3. What is a kernel?

Kernal is the core of any operating system. Kernal acts as a middle man between computer hardware and operating system and controls everything on a computer.It is the first program that is loaded when a system starts.

4. What does uname command do?

<b>uname </b> is reporting command is Linux that is used to retrieve basic information about a computer’s hardware and software.

Synatax: uname [options]

5. What does whoami do?

6. Please Explain LILO?

7. What is the difference between a and A?

8. What is the name and the UID of the administrator user?

9. What does ls -R do?

10. How to list all files, including hidden ones, in a directory?

11. What is LD_LIBRARY_PATH?

12. What are the Linux boot files?

13. What is grep command do?

14. What is difference between absolute and relative path?

15. What is Samba? Why is it used?

16. Please Provide Linux command to remove a directory with its contents?

17. Which command will show you free/used memory? Does free memory exist on Linux?

18. What is the difference between soft and hard mounting points?

19. What is SSH? How to connect to a remote server via SSH

20. How to tranfer a local file to a remote server in Linux

21. What is Virtual Memory?

22. List the basic components of Linux?

23. What is a shebang line?

24. How do you move files in Linux?

25. What does the command env do?

26. What does chmod +x FILENAMEdo?

27. How to add a new system user without login permissions?

28. What is CLI?

29. What is the difference between Telnet and SSH?

30. What does set -o do?

31. Difference between swap partition and swap file?

32. What does comm do and how to use it?

33. How to get the difference between two files in Linux?

34. How to add/remove a group from a user?

35. What is the full form of grep?

36. What is an A record, an NS record, a PTR record, a CNAME record, an MX record?

37. What does Sar provide? Where are Sar logs stored?

38. What is a zombie process?

39. What is a Split-Horizon DNS?

40. What is typical size for a swap partition under a Linux system?

41. What is an inode?

42. What is the difference between an environment and a local variable?